Testarossa's 78 KZ1000 Fighter Build

Good score Josh! At least it seems a little easier to find the pre 1980/1981 998cc heads! finding one of those for my bike is downright painful!

Yours looks to be in great shape!

JakeB wrote:

testarossa wrote:

You can see the round cam caps in this pic.

EDIT: when I say cam caps I mean the cam end plugs.

i am not talking about the cam plugs jake.i am talking about the way the head is cast on the outside.some years are rounded and some are more square.

here you can see the way the casting is more round.



the head on your z1r is probably more square.


no big,

leon

Gotcha, I never realized that the heads with the square-end valve covers used the same cam end plugs as the round-end ones.

The j style heads have more squared off cam end plugs though right?

the j heads have a bolt down through the cam plug,

leon

JakeB wrote:

testarossa wrote:

You can see the round cam caps in this pic.

EDIT: when I say cam caps I mean the cam end plugs.

Yes the end plugs are the same for Z1 / KZ's right up to the J model. 81-83 ,I believe, have the metal covering on rubber plug, 83-84 GPZ are plain rubber and both are bolt through type.

Looking at the photo, I was initially thrown off by the MKll rocker gasket on a '73-78 style head.There's no casting underneath the gasket btween 1&2 & 3&4 exhaust side. BTW, 79 LTD's are a unique deal MKll engine covers but 15 tooth crank centrepin and Z1 style cases, not MKll.

531blackbanshee wrote:

JakeB wrote:

testarossa wrote:

You can see the round cam caps in this pic.

EDIT: when I say cam caps I mean the cam end plugs.

i am not talking about the cam plugs jake.i am talking about the way the head is cast on the outside.some years are rounded and some are more square.

here you can see the way the casting is more round.

the head on your z1r is probably more square.


no big,

leon

It's funny you use that pic Leon, the owner of that bike wants me to make a diamond plate drip pan for that bike and a few of his others.......I sure could use a set of Keihin FCR33's........ :woohoo:

adam,
it was the first one i came across and being as how most members are familiar with it i thought that it would make a good example.
funny how we come on here to show how we mod our own bikes and then other folks go hey maybe he could do such and such for me.

seems like a win win for us.
we get to help out some other like minded folks and we make a little "side money" to help continue our projects.

i believe that is what this whole forum deal is supposed to be.

leon

I scored another piece of the puzzle today on ebay. The auction was listed as 0.410" lift Z1 cams with not too much other info. Supposedly never installed. Price was BIN $150 so I went ahead and jumped on it, not knowing exactly what I was getting. I figure if worse comes to worse I should be able to sell some NOS cams for better than that, right? Well the seller just got back to me, and they are APE K410 cams, YES! My new head just found it's buddies. Now I just have to get my 1075 pistons, and phase two will be well under way. Here's a link to the auction: cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll...geName=STRK:MEWNX:IT

Now on to my issues with the current engine setup. First, I get a vibration only on decel from about 3000 rpm down to 2000. It happens in any gear, even neutral. Under a load, or no load. There is no vibration under acceleration just on decel. Any ideas?

Next is those darn VM26 carburetors. I have them jetted just fine with one notable exception. It goes dead rich when you just start to get in the throttle. Right at the moment that you get the clutch out the air to fuel ratio drops to 10:1 and the bike stumbles. I have gone down to #15 pilots with no change in this behavior. The mixture screws are adjusted to keep the air to fuel ratio at about 14:1 when idling. I have asked about this in a couple of different threads, and I'm stumped. It's super annoying because it forces you to take off like a hooligan all the time. Not that I wouldn't do it on my own, but I want the choice dammit. :evil:

Finally, it has been using some oil and seems to smoke a little only under engine braking. I decided to run a compression test. With cold cylinders and throttle wide open, I got 140, 120, 130, 150. Not too thrilling, but I can live with that until I get all the parts together for the 1075.

testarossa wrote: ... get a vibration only on decel from about 3000 rpm down to 2000. It happens in any gear, even neutral. Under a load, or no load. There is no vibration under acceleration just on decel. Any ideas?
... VM26 carburetors... goes dead rich when you just start to get in the throttle. Right at the moment that you get the clutch out the air to fuel ratio drops to 10:1 and the bike stumbles. I have gone down to #15 pilots with no change in this behavior. The mixture screws are adjusted to keep the air to fuel ratio at about 14:1 when idling....

Presupposing:
Perfectly clean carb internals with as new OEM carb parts:
O-52 needle jet;
5DL31 jet needle (with clip in middle #3 position);
1.5 Throttle valve cutaway;
pilot jet 15;
pilot screw 1.0 ± ⅛ turn out;
service fuel levels at 3 ± 1 mm.

Would assure:
Advancer isn't sticking (may require lube, or clean and lube);
Motor mounts are tight;
Chain properly lubed and adjusted, and not kinked.

Good Fortune!

Patton wrote:
Presupposing:
Perfectly clean carb internals with as new OEM carb parts:
As clean as I can get them. 3 days in parts washer, 1 hr each in ultrasonic cleaner, each passage blown through with aerosol carb cleaner then shop air. New rebuild kits from Z1E

O-52 needle jet;
Not sure on this one, whatever is in there is in there.

5DL31 jet needle (with clip in middle #3 position);
Yes on the needle ID, but currently the clip is on the 5th(richest) position. Previously it was on the 4th with similar results only the AFR was a little lean from 1/4-3/4 throttle. Maybe I need to go up one more main jet size and get the needles back to the third clip. Currently running #125 mains, pods, 4-1 exhaust, and I'm at sea level.(Houston)

1.5 Throttle valve cutaway;
yes

pilot jet 15;
yes

pilot screw 1.0 ± ⅛ turn out;
yes

service fuel levels at 3 ± 1 mm.
yes, verified by clear tube method.

Would assure:
Advancer isn't sticking (may require lube, or clean and lube);
Shouldn't be an issue, as I have installed a Dyna 2000 ignition. All advance happens electronically. I timed it with a strobe when installed, and verified advance function at that time. I guess I could re-visit this just to make sure nothing has gone wrong.

Motor mounts are tight;
Checked before first ride and then daily for the first week or so. I'll recheck, but it has always exhibited these symptoms. Good to rule this out.

Chain properly lubed and adjusted, and not kinked.
New Renthal 530 X ring chain, cleaned, lubed, and adjusted per the manual. No Kinks. Chain and sprockets are all new with about 500 miles to date since installed.

Good Fortune!

One other item of note, the vibration on engine braking is definitely coming from the lower part of the engine. I am running a welded KZ900 crank that I purchased from another trusted member and the transmission is stock to the KZ1000. All the roller bearings seemed good when I was in there. Transmission gears all appeared normal with no scoring, discoloration, or unusual wear. Everything seemed to roll smooth in my hands before it was assembled. It's very slight, and may be normal. I never got to ride the bike before it was torn down, and I have never ridden a stock KZ1000 for that matter. It's just that none of my other bikes have ever really vibrated on decel quite like this.

I'm thinking crank twisted, I know you bought from trusted member but he prolly didn't know it may have been twisted either. These things happen and I don't get excited about it. I'm not sure if there is a good way to tell other than tearing off the top end and sliding a rod threw the wrist pin holes. Sucks, I know, but may be necessary

Patton wrote:

testarossa wrote: ... get a vibration only on decel from about 3000 rpm down to 2000. It happens in any gear, even neutral. Under a load, or no load. There is no vibration under acceleration just on decel. Any ideas?
... VM26 carburetors... goes dead rich when you just start to get in the throttle. Right at the moment that you get the clutch out the air to fuel ratio drops to 10:1 and the bike stumbles. I have gone down to #15 pilots with no change in this behavior. The mixture screws are adjusted to keep the air to fuel ratio at about 14:1 when idling....

Presupposing:
Perfectly clean carb internals with as new OEM carb parts:
O-52 needle jet;
5DL31 jet needle (with clip in middle #3 position);
1.5 Throttle valve cutaway;
pilot jet 15;
pilot screw 1.0 ± ⅛ turn out;
service fuel levels at 3 ± 1 mm.

Would assure:
Advancer isn't sticking (may require lube, or clean and lube);
Motor mounts are tight;
Chain properly lubed and adjusted, and not kinked.

Good Fortune!

i was thinking the same thing. it seems like a transition issue ,could be the advancer, or needle position ? are u stock or dyna 2000? congrats on the cams. great steel.how about the spings in the back clutch basket , for that vibration? did u check them out, when it was apart.?